The present invention relates to a semiconductor structure, and particularly to a temperature control device for an optoelectronic device and a germanium photodetector for silicon waveguide, and methods of manufacturing the same, and methods of operating the same.
A semiconductor waveguide may be employed in microphotonic devices to enable high efficiency long range transmission of light over distances in the micrometer range or in the millimeter range. The semiconductor waveguide typically employs a single crystalline semiconductor material to minimize signal loss due to absorption of light. The semiconductor material in the semiconductor waveguide has a relative high refractive index. For example, silicon and germanium have a refractive index of about 3.45 and about 4.0, respectively. A dielectric material having a lower refractive constant surrounds the semiconductor waveguide so that a total reflection condition is satisfied at the interface between the semiconductor waveguide and the dielectric material for light impinging on the interface at a glancing angle. The semiconductor wave guide may thus be employed to transmit light having a wavelength greater than the wavelength corresponding to the band gap of the semiconductor material. Typically, infrared lights are employed in the semiconductor waveguide.
Many microphotonic devices manipulate the light in the semiconductor waveguide in some way. For example, the light in the semiconductor waveguide may be absorbed, reflected, or induced to change the phase. Many of the prior art methods that accomplish such optical manipulation employ exotic materials or special processing steps that are not typically employed in standard complementary metal-oxide-semiconductor (CMOS) processing steps, thereby increasing the manufacturing cost and processing complexity.
In view of the above, there exists a need to provide a structure that manipulates the light in a semiconductor waveguide with standard CMOS processing steps, and methods of manufacturing the same. Particularly, there exists a need to provide a structure that modulates the phase of the light in the semiconductor waveguide with standard CMOS processing steps, and methods of manufacturing the same.
Further, performance of many optoelectronic devices is temperature sensitive. For example, performance of a semiconductor laser device is significantly affected by temperature variation. In a semiconductor chip integrating conventional semiconductor devices and optoelectronic devices, the performance of optoelectronic devices may be affected significantly due to the heat generated by conventional semiconductor devices and transferred to the optoelectronic devices. Thus, it is necessary to stabilize the temperature of the optoelectronic devices to provide stable operation of the optoelectronic devices within the semiconductor chip.
While placing optoelectronic devices at a location far away from the conventional semiconductor devices the thermal effect on the performance of the optoelectronic devices, such a design lowers the areal density of the conventional semiconductor devices or the optoelectronic devices. Thus, an integrated semiconductor chip including conventional semiconductor devices and optoelectronic devices at high density without adverse impact on the performance of the optoelectronic devices due to the thermal effects on the optoelectronic devices is desired.